In a heterogeneous network (Hetnet), downlink transmit power of a macro base station and that of a micro base station are different, resulting that a downlink coverage radius of the macro base station is different from a downlink coverage radius of the micro base station. Generally, the downlink coverage radius of the macro base station is greater than the downlink coverage radius of the micro base station. However, uplink transmit power, of a same terminal (UE), in sending an uplink signal to the macro base station and that in sending an uplink signal to the micro base station are the same; and therefore, an uplink coverage radius of the macro base station and that of the micro base station are equal. This situation is an uplink-downlink coverage imbalance problem in the Hetnet.
Because of the uplink-downlink coverage imbalance, a UE in a handover area of the Hetnet is easily subject to the following problems: power of the UE in the handover area is controlled by a micro base station with better uplink signal quality, and the micro base station instructs, when quality of a received uplink signal of the UE is higher than a threshold, the UE to reduce uplink transmit power; however, a serving base station of the UE is determined by quality of a downlink signal. For a UE whose downlink signal from a macro base station is of better quality in the handover area, its serving base station is the macro base station. However, quality of an uplink signal from the UE to the macro base station is originally relatively poor, that is, quality of an uplink signal from the UE to the macro base station is inferior to quality of an uplink signal from the UE to the micro base station, and the micro base station further instructs the UE to reduce uplink transmit power, which may result that the UE is out-of-synchronization with the macro base station in an uplink direction, that is, a communication connection with the macro base station may be disconnected.